1. Field of the Invention
The present invention is related to a method of performing traffic steering in a wireless network system, and more particularly, to a method of performing high efficient and real-time traffic steering in a wireless network system.
2. Description of the Prior Art
With rapid development in technology, a user may easily connect to a network using desktop computers, notebook computers, personal digital assistants (PDAs) or smart phones. As successive generations of operating standards proliferate, a wireless device is sometimes constructed to be operable in conformity with multiple communication standards associated with a single radio communication system-type or multiple communication system-types. For instance, a multi-mode device may provide a user with the capability of communicating with an Internet Protocol (IP)-based radio network and a 3rd Generation Partnership Project (3GPP)-based cellular network.
According to relevant 3GPP specifications (such as TS. 34.108), a base station is configured to broadcast various system information blocks to a user equipment (UE). System information block type 1 (SIB1) contains cell access related information when evaluating if a user equipment is allowed to access a cell, such as public land mobile network (PLMN) identity list, tracking area code, cell identity, information for cell selection, maximum power value (p-Max), frequency band indicator, scheduling information, time division duplex (TDD) configuration, system information window length and system information value tag. In a wireless network system, radio access network (RAN) rules associated with interworking between a 3GPP-based network and an IP-based network are included in a system information block type 17 (SIB17). SIB1 uses a fixed schedule with a periodicity of 80 ms and repetitions made within 80 ms. Upon receiving the SIB1 message, the user equipment can decide how to access the SIB17 message. Based on the RAN rule, the user equipment may perform traffic steering between the 3GPP-based network and the IP-based network, such as data offloading from the 3GPP-based network to the IP-based network. If it is determined that the 3GPP-based network is still overloaded, the base station is configured to update the threshold of the RAN rule in SIB17 and notify the user equipment to read the updated SIB17 message in SIB1 for encouraging the user equipment to steer traffic from the 3GPP-based network.
In the prior art traffic steering method, the efficiency of the base station may be influenced when the threshold of the RAN rule needs to be updated many times before a congested network is sufficiently offloaded. The user equipment is required to read both SIB1 and SIB17 each time when the threshold of the RAN rule is updated. Also, since the user equipment user only reads SIB1 periodically, it may not be able to immediately respond to any update made to the RAN rule. Therefore, there is a need for a method of performing high efficient and real-time traffic steering in a wireless network system.